Those that take a deconstructive approach to religion identify closely with the work of Jacques Derrida, especially his work later in life. According to Slavoj Žižek, in the mid-to-late 1980s Derrida's work shifted from constituting a radical negative theology to being a form of Kantian idealism. John D. Caputo describes Derrida's work in the 1970s as a Nietzschean free play of signifiers while he describes Derrida's work in the 1990s as a "religion without religion."